Wetting reversal surfactant for drilling fluid

Abstract

The invention discloses a wetting reversal surfactant for drilling fluid. The wetting reversal surfactant is characterized by comprising the following components in percentage by weight: 10 percent of dodecyltrimethylammonium bromide, 15 percent of heavy oil, 20 percent of fatty acid and 55 percent of water. The surfactant does not have influence on the performance of the drilling fluid and has positive charges so as to be mutually absorbed to a hydrophilic rock layer around an oil well with negative charges; the surfactant is adhered to a rock core through a cationic surfactant; the wetting reversal surfactant is covered by a hydrophobic lipophilic group layer; and thus the hydrophilic rock layer is reversed into a lipophilic hydrophobic rock layer to fulfill the aim of replenishing oil and stopping water.

Description

technical field [0001] The present invention relates to a wetting inversion surfactant for drilling fluid. Background technique [0002] As the drilling progresses, the hydrophilic cuttings in the formation continuously invade the oil-based drilling fluid, and the existence of a large amount of hydrophilic substances makes it difficult to control the rheology of the drilling fluid, the fluid loss of the drilling fluid increases, and the demulsification voltage increases significantly. decline. At the same time, during the drilling, completion, production and stimulation of oil wells, water accumulates on the well wall, causing water plugging, which reduces the permeability of crude oil, that is, hinders the flow of crude oil from the formation to the oil well, and reduces the production of the oil well. If the well wall is soaked, it is very easy to cause well wall instability and accidents such as oil well collapse. Contents of the invention [0003] In view of the abov...

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Problems solved by technology

[0002] As the drilling progresses, the hydrophilic cuttings in the formation continuously invade the oil-based drilling fluid, and the existence of a large amount of hydrophilic substances makes it difficult to control the rheology of the drilling fluid, the fluid loss of the drilling fluid increases, and the demulsification voltage increases significantly. decline

At the same time, during the drilling, completion, production and stimulation of oil wells, water accumulates on the well wall, causing water plugging, which reduces the permeability of crude oil, that is, hinders the flow of crude oil from the formation to the oil well, and reduces the production of the oil well. If the well wall is soaked, it is very easy to cause the instability of the well wall and easily cause accidents such as oil well collapse

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